Finding Out How Plants Eat: teacher key

How Plants Grow, grade 8 edition, written for 8th grade. How did people learn what plants are made of and how they sense light? Follow the experiments, then see how seeds travel and wait.

Read the book. Print this page for the key.

Questions and answers

1. What did Priestley's 1772 report give the first evidence of?
   • That gases take part in photosynthesis (answer)
   • That roots grow toward light
   • That seeds need darkness
2. Why did Ingen-Housz's dark chamber test matter?
   • It showed plants cannot grow in glass
   • It showed a plant in the dark uses up oxygen (answer)
   • It showed seeds float
3. What did the Darwins find in 1880?
   • Roots make oxygen
   • Pollen sticks to fur
   • A plant detects light at its tip (answer)
4. Why is cross-pollination preferable?
   • It produces more genetic diversity (answer)
   • It makes bigger petals
   • It needs no insects
5. What is a tropism?
   • A kind of seed coat
   • A growth movement set by the direction of a stimulus (answer)
   • A tiny opening in a leaf

Words

• stomata: tiny leaf openings
• tropism: growth movement
• pollinators: pollen carriers
• chlorophyll: green plant stuff